Very late effects of postoperative atrial fibrillation on outcome of coronary artery bypass graft surgery

Colchicine in atrial fibrillation: are old trees in bloom?

Colchicine is a widely used drug that was originally used to treat gout and rheumatic diseases. In recent years, colchicine has shown high potential in the cardiovascular field. Atrial fibrillation (AF) is a cardiovascular disease with a high incidence. One of the most frequent complications following cardiovascular surgery is postoperative atrial fibrillation (POAF), which affects patient health and disease burden. This article reviews the research status of colchicine in AF and summarizes the relevant progress.

Comparison of the Efficacy of Atorvastatin and Rosuvastatin in Preventing Atrial Fibrillation after Coronary Artery Bypass Grafting: A Double-Blind Randomized Comparative Trial

Background

Atrial fibrillation (AF) is a supraventricular tachyarrhythmia characterized by disorganized atrial activity and subsequent mechanical atrial failure. Postoperative AF is a frequent complication of coronary artery bypass grafting (CABG). Although there is evidence of decreased AF after CABG with statin usage, information is scarce regarding a direct comparison between atorvastatin and rosuvastatin. The present study was conducted to compare the efficacy of rosuvastatin and atorvastatin in preventing post-CABG AF.

Methods

The present double-blind randomized comparative clinical trial selected CABG candidates with stable ischemic heart disease or acute coronary syndromes. Atorvastatin (40 mg per day) or rosuvastatin (20 mg per day) was prescribed 1 week before surgery, and the outcomes were compared.

Results

Two-hundred patients, 100 cases in each group, completed the study. Twenty-five patients in each group were female, and the mean age was 59.30±8.42 years in the rosuvastatin group and 60.13±9.40 years in the atorvastatin group (P=0.513). The frequency of AF was 31% in the atorvastatin group and 27% in the rosuvastatin group (P=0.534). No significant differences existed between the groups concerning the length of hospital and ICU stay (P=0.333 and P=0.161) and in-hospital and 3-month mortality (P=0.315 and P=0.648). A subgroup analysis of only patients with stable ischemic heart disease could not detect a significant difference between the study groups in any of the investigated outcomes. Our logistic regression analysis showed an association only between age and the incidence of AF after CABG (OR, 1.12; 95% CI, 1.05 to 1.20; P<0.01).

Conclusion

Rosuvastatin and atorvastatin are similar concerning the prevention of post-CABG AF, but there is a need for future well-designed multicenter studies on this topic.

Atrial fibrillation after cardiac surgery: A systematic review and meta-analysis

OBJECTIVE

New-onset postoperative atrial fibrillation (POAF) after cardiac surgery is common, with rates up to 60%. POAF has been associated with early and late stroke, but its association with other cardiovascular outcomes is less known. The objective was to perform a meta-analysis of the studies reporting the association of POAF with perioperative and long-term outcomes in patients with cardiac surgery.

METHODS

We performed a systematic review and a meta-analysis of studies that presented outcomes for cardiac surgery on the basis of the presence or absence of POAF. MEDLINE, EMBASE, and the Cochrane Library were assessed; 57 studies (246,340 patients) were selected. Perioperative mortality was the primary outcome. Inverse variance method and random model were performed. Leave-one-out analysis, subgroup analyses, and metaregression were conducted.

RESULTS

POAF was associated with perioperative mortality (odds ratio [OR], 1.92; 95% confidence interval [CI], 1.58-2.33), perioperative stroke (OR, 2.17; 95% CI, 1.90-2.49), perioperative myocardial infarction (OR, 1.28; 95% CI, 1.06-1.54), perioperative acute renal failure (OR, 2.74; 95% CI, 2.42-3.11), hospital (standardized mean difference, 0.80; 95% CI, 0.53-1.07) and intensive care unit stay (standardized mean difference, 0.55; 95% CI, 0.24-0.86), long-term mortality (incidence rate ratio [IRR], 1.54; 95% CI, 1.40-1.69), long-term stroke (IRR, 1.33; 95% CI, 1.21-1.46), and longstanding persistent atrial fibrillation (IRR, 4.73; 95% CI, 3.36-6.66).

CONCLUSIONS

The results suggest that POAF after cardiac surgery is associated with an increased occurrence of most short- and long-term cardiovascular adverse events. However, the causality of this association remains to be established.

New-onset postoperative atrial fibrillation impact on 5-year clinical outcomes and costs

OBJECTIVE

The impact of new-onset postoperative atrial fibrillation (POAF) following coronary artery bypass grafting (CABG) surgery on long-term clinical outcomes and costs is not known. This subanalysis of the Veterans Affairs "Randomized On/Off Bypass Follow-up Study" compared 5-year outcomes and costs between patients with and without POAF.

METHODS

Of the 2203 veterans in the study, 100 with pre-CABG atrial fibrillation (93) or missing data (7) were excluded (4.8%). Unadjusted and risk-adjusted outcomes were compared between new-onset POAF (n = 551) and patients without POAF (n = 1552). Five-year clinical outcomes included mortality, major adverse cardiovascular events (MACE, comprising mortality, repeat revascularization, and myocardial infarction), MACE subcomponents, stroke, and costs. A stringent P value of ≤.01 was required to identify statistical significance.

RESULTS

Patients with POAF were older and had more complex comorbidities. Unadjusted 5-year all-cause mortality was 16.3% POAF versus 11.9% no-POAF, P = .008. Unadjusted cardiac-mortality was 7.4% versus 4.8%, P = .022. There were no differences between groups in any other unadjusted outcomes including MACE or stroke. After risk adjustment, there were no significant differences between groups in 5-year all-cause mortality (POAF odds ratio, 1.19; 99% confidence interval, 0.81-1.75) or cardiac mortality (odds ratio, 1.51, 99% confidence interval, 0.88-2.60). Adjusted first-year post-CABG costs were $15,300 greater for patients with POAF, but 2- through 5-year costs were similar.

CONCLUSIONS

No 5-year risk-adjusted outcome differences were found between patients with and without POAF after CABG. Although first-year costs were greater in patients with POAF, this difference did not persist in subsequent years.

Cost-effectiveness of colchicine treatment on post-operative atrial fibrillation events in patients of major cardiac surgery

Aims

Post-operative atrial fibrillation (POAF) occurs in 20-50% of patients amid post-operative stay after Cardiac Surgery. We intend to determine whether colchicine therapy in patients undergoing cardiac surgery is a cost-effective strategy for prevention of POAF. To undertake cost utility analysis and calculate incremental cost utility ratio (ICUR) for colchicine therapy in these subgroup of patients.

Methods and results Design

Decision tree model to calculate the ICUR comparing two treatment strategies in patients undergoing cardiac surgery. One wherein patients received colchicine along with usual care and second where they received placebo or just usual care. Cost utility analysis was undertaken using relevant data from the systematic review and meta-analysis of the available randomized controlled trials till June 2016 and mean cost calculations from validated available sources across various jurisdictions.

Results

Colchicine treatment based on mean costs for life expectancy calculated at 10 years' post-surgery using recommended discounting rates of 3.5% was € 17544.80 cheaper per quality-adjusted life-year (QALY) gained. The incremental cost is negative and the incremental effect (QALY) is positive (South East quadrant), Hence the intervention of colchicine treatment is unequivocally cost-effective, meaning it is dominant and achieves better outcomes at a lower cost.

Conclusion

Our findings provide a benchmark for current and future analyses relating to effectiveness of colchicine on POAF events after cardiac surgery. Currently, there are few reports that provide cutting edge estimates of the higher expenses associated with POAF. Future analyses should likewise explore the impact of added costs from using pharmacologic efforts to prevent and treat POAF after cardiac surgery.

Obesity and postoperative atrial fibrillation in patients undergoing cardiac surgery: Systematic review and meta-analysis

INTRODUCTION

Post-operative atrial fibrillation (POAF) is one of the most common complications following cardiac surgery. However, it is unclear whether there is a relationship between obesity and POAF. We thus assessed all available evidence investigating the association between obesity and POAF, also considering any link between POAF and other post-operative conditions such as mortality, stroke, myocardial infarctions and respiratory complications.

METHODS

Five electronic databases were searched and relevant studies were identified. Data was extracted and meta-analyzed from the identified studies.

RESULTS

We found that obese patients had significantly higher odds of POAF when compared with non-obese patients (P=0.006). There was also significant heterogeneity among the identified studies. POAF when compared with no-POAF was associated with an increased risk of stroke (P<0.0001), 30-day mortality (P=0.005) and respiratory complications (P<0.00001). However, we found no significant link between POAF and myocardial infarctions (P=0.79).

CONCLUSIONS

Our findings suggest that obesity is associated with a moderately higher risk of POAF. While POAF is also associated with an increased incidence of stroke, 30-day mortality and respiratory complications, further studies must be conducted before conclusions can be made about the long-term outcomes.